Climate scientists agree the Earth will be hotter by the end of the century, but their simulations don’t agree on how much. Now a study suggests the gloomier predictions may be closer to the mark.

“Warming is likely to be on the high side of the projections,” said John Fasullo of the National Center for Atmospheric Research in Boulder, Colo., a co-author of the report, which was based on satellite measurements of the atmosphere.

That means the world could be in for a devastating increase of about eight degrees Fahrenheit by 2100, resulting in drastically higher seas, disappearing coastlines and more severe droughts, floods and other destructive weather.

Such an increase would substantially overshoot what the world’s leaders have identified as the threshold for triggering catastrophic consequences. In 2009, heads of state agreed to try to limit warming to 3.6 degrees, and many countries want a tighter limit.